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Published on: July 30, 2017
Facial cooling and peripheral chemoreflex mechanisms in humans
J F Argacha1, O Xhaët, M Gujic
1Department of Cardiology, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium. jfxa@skynet.be
Acta Physiologica (Oxford, England)
|May 24, 2008
Summary
Facial cooling enhances the body's natural response to low oxygen levels and breath-holding. This effect stimulates breathing and heart rate regulation, suggesting improved chemoreflex function.
Area of Science:
- Physiology
- Cardiorespiratory control
- Human autonomic nervous system
Background:
- Peripheral chemoreceptors detect arterial oxygen levels, influencing ventilation and heart rate.
- Facial cooling is known to elicit the diving reflex, affecting cardiorespiratory function.
Purpose of the Study:
- To investigate whether facial cooling potentiates peripheral chemoreflex mechanisms.
- To assess the impact of facial cooling on ventilatory and bradycardic responses.
Main Methods:
- Assessed ventilatory response to hypoxia and bradycardic response during apnoeas in 12 healthy subjects.
- Measured minute ventilation, O2 saturation, and RR interval (heart rate variability) with facial exposure to 23°C and 4°C air.
- Recorded standard deviation of RR interval (SDNN) as a marker of cardiac vagal activity.
Main Results:
- Facial cooling (4°C air) significantly increased the ventilatory response to hypoxia.
- Cold air exposure amplified the bradycardic response during hypoxic apnoeas (31% vs. 17% RR interval increase).
- Facial cooling elevated cardiac vagal activity (SDNN) under normoxic, hypoxic, and apnoeic conditions.
Conclusions:
- Facial cooling enhances peripheral chemoreflex sensitivity to hypoxia in humans.
- Combined diving reflex and chemoreflex activation by facial cooling potentiates cardiac vagal activity and bradycardia.
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